“Radiation Risks and Pediatric Computed Tomography (CT): A Guide for
Health Care Providers.” 5 There are several solutions being developed to address
this problem. Solutions addressing better
control and effectiveness of the radiation
being utilized are being developed by
equipment manufacturers. Radiologists
are attempting to develop better scan
protocols to find the best compromise
between image quality and patient dose. 6
Hospital administrators are charged with
funding the costs associated with these
changes. The latest players in this issue
are groups such as The Joint Commission, Centers for Medicare and Medicaid
Services, commercial insurance payers,
and the general public. The Federal Drug
Administration (FDA) reported in a February 2010 white paper on their initiative
to reduce unnecessary radiation exposure
from medical imaging. 7These groups are
beginning to demand documentation of
steps taken to reduce doses. All of these
factors are helping drive solutions to this
problem.

Groups are beginning to demand documentation of steps takento reduce doses. All of these factors are helping drive solutionsto this problem.

DiscussionMethods

The review of research done by others
illustrates the data needed to frame the
subject of patient dose and CT technology. Searches were conducted for
articles using the following databases:
EBSCOhost, American Medical Association, Radiology, and Radiologic Society
of North America. Keyword searches
included: CT, CAT, computed tomography, computed tomography technology advancement, CT radiation dose,
and spiral vs. conventional CT radiation doses. Articles cited in the review
were peer reviewed pieces from medical
journals including: European Journal of
Radiology, British Journal of Radiology,
Emergency Radiology, European Radiology, New England Journal of Medicine,
and American Journal of Neuroradiology.
Articles were selected on the basis of their
peer review status and level of relevancy
to the progression of the discussion of
the main subject matter.

A study in Germany concluded there was
a significant increase of the mean CT
dose index (CTDI). 8 When comparing
quad-slice scanners to single-slice and
dual-slice scanners, average CTDI increased for all examinations by 17% and
53%, respectively. Conversely, the dose
length product (DLP) decreased by 22%
for dual-slice scanners.

A 2007 study from Columbia University outlined the rapid increase in
CT use. 5 There are currently more than
62 million CT exams performed in the
United States annually compared to only
3 million in 1980. The study also illustrated the frequency of patients having
multiple scans in the same day, showing
that 30% of patients had three scans, 7%
had five scans and 4% had nine or more.
The need for additional physician education was evident. In a recent survey of
radiologists and ED physicians, 75% of
the group as a whole significantly underestimated patient radiation dose. This
broke out into 53% of radiologists and
91% of ED. 5

A 2001 study was conducted illustrating a direct comparison of spiral and
conventional CT scanners. 9 A surprising
contrast in results was shown. The CTDI
for conventional CT examinations of the
chest, liver, pancreas, pelvis, and lumbar
spine (in cases of fracture) led to significantly higher doses than did spiral CT. 9
The article showed an average decrease
of 38% for spiral CT when compared to
conventional CT. This article did echo
the concern about rising exam numbers
in all areas of CT utilization.

The European Journal of Radiologypublished an article in 2004 that evaluatedsingle-slice and multi-slice CT scannersin the performance of high resolutionexams of the lung and virtual bronchos-copy. 10 It concluded that any new pro-tocols should be evaluated and bench-marked against the current protocols tomeasure difference to patient outcomeand providing the best clinical informa-tion with the least possible dose to thepatient. Other considerations were theimpact of excessively large image num-bers on PACS and post processing imag-ing equipment.